• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.590-598
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• 2011

Bacterial assimilation of $CO_2$ into stable biomolecules using electrochemical reducing power may be an effective method to reduce atmospheric $CO_2$ without fossil fuel combustion. For the enrichment of the $CO_2$-fixing bacteria using electrochemical reducing power as an energy source, a cylinder-type electrochemical bioreactor with a built-in anode compartment was developed. A graphite felt cathode modified with neutral red (NR-graphite cathode) was used as a solid electron mediator to induce bacterial cells to fix $CO_2$ using electrochemical reducing power. Bacterial $CO_2$ consumption was calculated based on the variation in the ratio of $CO_2$ to $N_2$ in the gas reservoir. $CO_2$ consumed by the bacteria grown in the electrochemical bioreactor (2,000 ml) reached a maximum of approximately 1,500 ml per week. Time-coursed variations in the bacterial community grown with the electrochemical reducing power and $CO_2$ in the mineral-based medium were analyzed via temperature gradient gel electrophoresis (TGGE) of the 16S rDNA variable region. Some of the bacterial community constituents noted at the initial time disappeared completely, but some of them observed as DNA signs at the initial time were clearly enriched in the electrochemical bioreactor during 24 weeks of incubation. Finally, Alcaligenes sp. and Achromobacter sp., which are capable of autotrophically fixing $CO_2$, were enriched to major constituents of the bacterial community in the electrochemical bioreactor.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.101-107
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• 2012

Objective: The aim of this study is to investigate service design cases by online service companies and suggests framework to understand service design of them. Background: Recently, exploratory service design cases by online service companies such as Google, Apple, and NHN has been developed. Service design and online service experience design has been booming among user experience professionals but these two areas are not clearly defined. It is interesting to study the definition and key factors of service design and online service experience design. Moreover, investigating service design cases by online service companies is needed. Method: Due to diversification of service design cases by online service companies, this study has reviewed online resources and literatures about top 5 online service companies in USA and Korea. Furthermore, this study used expert interview who worked for service design at NHN. To understand the attributes of service design cases, this study developed 3 types of service design classifications scheme such as service design as extension of online service, space design and event service design. Finally, this study suggested a new framework for service design cases. Results: This study investigated service design cases by online service companies and suggests key issues and frameworks to uncover service design for online service. Conclusion: Service design cases for online service was analyzed by $2^*2$ matrix(extension, $enrichment^*product$, service) to explain characteristics and attributes. NHN's Knowledge-iN bookshelf at NHN library1 is a unique form of service design as a tool of enrichment of online experience. Application: The results of this study might help to understand service design cases and plan new service design for online service companies with structured framework.

• Journal of Environmental Science International
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• v.29 no.1
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• pp.79-93
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• 2020

To determine the size distributions of water-soluble inorganic ionic species (WSIS) in roadside aerosols, sampling experiments were carried out in the urban roadside area of Jeju City on August 2018 and January 2019 by using the eight-stage cascade impactor sampler. The mass of roadside aerosols were partitioned at 57% in fine fraction, 36-37% in coarse fraction, and 6-7% in giant fraction, regardless of summer and winter. The mass concentrations of WSIS except for Na+ and SO42- in roadside aerosols were higher in winter than in summer. The size distributions of Na⁺, Mg²⁺, Ca²⁺ and Cl^- were characterized by bimodal types with coarse particle mode peaking around 3.3-4.7 ㎛ and 5.8-9.0 ㎛. The size distributions of NO₃^- and K⁺ shifted from a single fine mode peaking around 0.7-1.1 ㎛ in winter to bimodal and/or trimodal types with peaks around coarse mode in summer. SO₄^2- and NH₄⁺ showed a single fine mode peaking around 0.7-1.1 ㎛. The MMAD of roadside aerosols was lower than that of Na⁺, Mg²⁺, Ca²⁺ and Cl-. Based on the marine enrichment factors and the ratio values of WSIS and the corresponding value for sea water, the composition of roadside aerosols in Jeju City may be practically affected by terrestrial sources rather than marine source.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.321-326
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• 1989

Eighty two bacterial strains have been isolated from five different soil and sewage samples by selective enrichment culture on m-toluate minimal medium. Two of these were identified as Pseudomonas capacia, one as P. putida, one as Yersinia intermedia, and one as Flavobaeterium odoratum. P. cepacia SUB37 appeared to carry plasmid superficially similar to TOL plasmid previously described in p. putida mt-2 and other two plasmids from Flavobacterium odorutum and Y. intermedia larger than that of p. putida mt-2. p. cepacia SUB37 was sensitive to streptomycin but resistant to rifampicin. P. cepacia SUB37 carrying plasmid metabolizes the hydrocarbons to benzoate and toluates via the corresponding alcohols and aldehydes. By the curing experiment, it appears that P. cepacia SUB37 carries TOL plasmid encoding for the enzymes responsible for the catabolism of toluene and xylene via benzoate and the toluates and then by meta pathway in the process of degradation of aromatic hydrocarbons. p. cepacia SUB37 degraded m-toluate rapidly to be very low level when it was fully grown.

• The Journal of Fisheries Business Administration
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• v.27 no.1
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• pp.15-45
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• 1996

The sustained economic growth cannot be expected without the balanced development in all the realms of industries. Korea has recorded the continuous high growth rate of economy, but it is now facing some difficulties in keeping the normal economic growth, because industrial workers do not like to work in some fields, the typical one of which is the fishery works. This thesis aims at studying the determinants of fishermen's job satisfaction(FJS) and the determinants of affecting the fishermen's trunover intention(FTI) to obtain and maintain the man power for fishing boats. This study assumes that the determinants which affact FJS are fishermen's work values, job characteristics, the attitude of accepting their fishery work, and that the determinants which affect FTI are FJS and their perceptions of labor market. This study concerns two kinds of Job satisfaction : one is an intrinsic satisfaction which comes directly from the work itself, and the other is an extrinsic satisfaction comes from the compensation for the work, but in this study “Pollnac's work satisfaction factor” is added as an additional determinant of FJS. There is a difference in job satisfactions between the individuals who have different work values. Some feel more satisfacttion than the others, which can be explained by the internal work values which assume the work is only a means for another objective of life. This study applies Hackman and 014ham's studies to the job characteristics that a worker's job satisfaction is positively related to the core job characteristis of the job. In addition, this study transformed their studies into variables. A job enrichment to reduce the simplicity of a work and make it more valueable can increase a job satisfaction, but an existing organization has limitation in redesigning the job for its enrichment. A reasonable answer about this matter can be obtained from the workers' subjective perceptins to highly regard the objective job characteristics. Worker's previews of fishery work also affect their job satisfaction because they are already informed of the details and charcteristics of the job that they have to carry out. A Job dissatisfaction causes their intention to leave jobs owing to general perceptions prevailing in labor markets.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.627-633
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• 2003

The PM$_{10}$ concentration and chemical composition in an western area of Busan were surveyed between March, 2001 and February, 2002. The mean concentration was 98.2 $\mu\textrm{g}$/㎥ with a range of 18.1 to 330.6 $\mu\textrm{g}$/㎥. The magnitude of metallic elements in PM$_{10}$ is as follows in decreasing order: K>Ca>Na>Al>Fe. The mean values of crustal enrichment factors for four elements (Cd, Ni, Pb and Zn) were all higher than 10, which presumably resulted from the effect of anthropogenic origin. Moreover, the wintertime values were higher than springtime and summertime values, possibly due to emissions westerly transported from industries around this area. The contribution of soil particle to airborne particle in the study area was estimated to be 9.5%.

• Journal of Radiation Protection and Research
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• v.21 no.2
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• pp.107-115
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• 1996

An electrolytic enrichment technique was used to measure low levels of tritium in seawater around the Korean peninsula. Tritium concentrations were determined for surface seawater samples collected from the East Sea, the South Sea, and the Yellow Sea. The tritium concentrations in surface seawater samples from the study area ranged from $0.12 BqL^{-1}\;to\;1.50BqL^{-1}$ with a mean value of $0.60{\pm}0.35 BqL^{-1}$. The means of the tritium concentration were $0.54{\pm}0.30 BqL^{-1}$ for the East Sea, $0.48{\pm}0.35 BqL^{-1}$ for the South Sea, and $0.77{\pm}0.32 BqL^{-1}$ for the Yellow Sea. The tritium concentrations in the sea areas did not show much difference no matter where the samples were taken. Due to the limited number and distribution of sampling points, no systematic change in tritium levels with latitude was observed. Measured tritium levels were similar to those observed in other data collected near Japan, but higher than mid-Pacific Ocean measurements.

• Journal of Families and Better Life
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• v.28 no.4
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• pp.1-13
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• 2010

The purpose of this study is to conduct base line research, which is based on requestion of international married immigrant women, for developing social adaptation and family enrichment program for those population who reside in Korea. The survey questionnaire was distributed to 142 international married immigrant women who reside in Seoul to research program participate satisfaction and requestion. Analyze the study results, frequency, percentage, t-test, ANOVA and Duncan-post test were utilized. As a result, overall satisfaction toward program that offered by organization was highly ranked. Visiting service showed high score of satisfaction but mentor service that strongly possess sacrifice showed lower score of satisfaction. Vocational and job-related skill improvement education presented less satisfied degree of satisfaction but cooking class, computer class, training education for native-speaking instructor present high level of satisfaction. Second, the requisition of target population, who did not participate program, presented lower than the satisfaction, still present high demand of variety area of program. Among them, assist child nurturing and vocational and job- related skill improvement education showed high demand. It enable to predict that they are eager to get support toward parent role and self-realization. Third, when the difference were analyzed to compare the subjective judgement toward life adaptation in Korea and the satisfaction for program user and the requisition of non-user, the meaningful differences were founded; especially, individuals who possess confident degree of computer skills and Korean(reading, speaking, and listening) showed higher degree of satisfaction to vocation and job-skill related improvement education. This study has a practical implication, which is based on the study results, on developing a program to support international married immigrant women and multicultural families to satisfactory settlement in Korea life and to maintain healthy families.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.4
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• pp.299-305
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• 2006

Aromatic L-amino acid transaminase is an enzyme that is able to transfer the amino group from L-glutamate to unnatural aromatic ${\alpha}-keto$ acids to generate ${\alpha}-ketoglutarate$ and unnatural aromatic L-amino acids, respectively. Enrichment culture was used to isolate thermophilic Bacillus sp. T30 expressing this enzyme for use in the synthesis of unnatural L-amino acids. The asymmetric syntheses of L-homophenylalanine and L-phenylglycine resulted in conversion yields of >95% and >93% from 150 mM 2-oxo-4-phenylbutyrate and phenylglyoxylate, respectively, using L-glutamate as an amino donor at $60^{\circ}C$. Synthesized L-homophenylalanine and L-phenylglycine were optically pure (>99% enantiomeric excess) and continuously pre-cipitated in the reaction solution due to their low solubility at the given reaction pH. While the solubility of the ${\alpha}-keto$ acid substrates is dependent on temperature, the solubility of the unnatural L-amino acid products is dependent on the reaction pH. As the solubility difference between substrate and product at the given reaction pH is therefore larger at higher temperature, the thermophilic transaminase was successfully used to shift the reaction equilibrium toward rapid product formation.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.121-128
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• 1998

In fields of operating or handling a hydrogen isotope facility, and of the technology for nuclear fusion source management, gas chromatography has been used as one of the practical techniques lot separation and enrichment of hydrogen isotopic gases including tritium. Chromatographic separation experiments of the hydrogen isotope mixture (hydrogen, deuterium and tritium) were carried out by use of a commercially available gas chromatograph. An aliquot of gas sample was injected by a specially designed vacuum sampler into the stream of inert carrier gas which went through the separation column under liquid nitrogen temperature. The complete separation of hydrogen isotopic molecules was observed with an alumina adsorbent partially deactivated by coating with 10% manganese chlorine. In addition, fairly good separation conditions were obtained without any appearance of nuclear spin isomers with shorter retention time, which would be available for the practical applications of the hydrogen isotope separation and enrichment.